Protective guard for lift trucks



y 1956 N. B. WATSON 2,754,019

PROTECTIVE GUARD FOR LIFT TRUCKS Filed Jan. 8, 1953 2 Sheets-Sheet l.ZEVVEn far Mrman J3. Z'zfaison July 10, 1956 N. B. WATSON PROTECTIVEGUARD FOR LIFT TRUCKS 2 Sheets-Sheet 2 Filed Jan. 8, 1953 United StatesPatent PROTECTIVE GUARD FOR LIFT TRUCKS Norman B. Watson, Chicago, Ill.,assignor to The Mercury Manufacturing Company, Chicago, Ill., acorporation of Illinois Application January 8, 1953, Serial No. 330,332

2 Claims. (Cl. 214-674) This invention relates generally to industrialmaterials handling equipment and more particularly to an overheadprotective guard for a lift and tiering truck.

Heretofore lifting and tiering trucks of the type having a lifting mastassembly equipped with a fork lift or the like have been provided withsome form of protective guard to insure an adequate measure of safetyfor the truck operator. For example, in one type of protective guardapparatus, the lift truck is equipped with an overhead canopy anchoreddirectly to the front and rear portions of the truck frame by boltedconnections or pipe sockets. Such type of protective guard issatisfactory for only such lift trucks as do not require frequentremoval of the power unit or storage batteries. Where daily service ofthe truck power unit is required, such a protective guard is awkward,cumbersome and highly restrictive of a facile servicing operation.

In an effort to overcome such deficiencies, the protective guardapparatuses heretofore provided have contemplated the utilization of ahinged canopy section so that a portion of the canopy guard can behingedly displaced in order to facilitate removal of batteries from abattery box. The utilization of a hinge structure, however, greatlyincreases the cost of the protective guard apparatus and themanipulation of the hinge section requires a more expensive andtime-consuming servicing operation particularly where frequent batterychanging is contemplated.

According to the principles of the present invention, an improvedprotective guard is provided for a lift truck of the type having alifting mast assembly pivotally connected to the truck body. Theprotective guard is pivotally mounted on the forward portion of thetruck frame and on the upper portion of the tiltable lifting mast. Theprotective guard forms an adequate canopy protection overhead so as toadequately insure a full measure of safety for the truck operator,however, overhead removal of batteries from the battery box can beconveniently effected without interference.

The pivotal mounting means provided between the protective guard and thetiltable lifting mast and also between the protective guard and thetruck frame permits the maintenance of the protective guard canopy in asubstantial horizontal position even though the lifting mast is movedforwardly and backwardly during a tilting operation.

The protective guard assembly of the present invention may beconveniently fabricated from a reduced number of highly simplifiedelements and is particularly efficient in practical operation.

It is an object of the present invention, therefore, to provide aprotective guard apparatus which overcomes the deficiencies of theprotective guard apparatus heretofore provided.

Another object of the present invention is to provide a protective guardcanopy which is at least partially supported on the tilting mastassembly and which will remain substantially horizontal even though thetilting mast is moved forwardly and backwardly.

Another object of the present invention is to provide a protective guardapparatus for a battery-powered lifting truck which will not interferewith the servicing of the power unit or the removal of batteries fromthe battery box.

Another object of the present invention is to provide a protective guardapparatus which may be conveniently fabricated from a reduced number ofsimplified elements at a substantial reduction of cost.

Many other advantages, features and additional objects of the presentinvention will become manifest to those versed in the art upon makingreference to the detailed description which follows and the accompanyingsheets of drawings in which a preferred structural embodiment of aprotective guard apparatus constructed in accordance with the principlesof the present invention is shown by way of illustrative example.

On the drawings:

Figure l is an elevational view of a lift truck incorporating aprotective guard apparatus according to the principles of the presentinvention;

Figure 2 is a plan elevational view of the lift truck shown in Figure 1;

Figure 3 is an enlarged fragmentary view showing addi-- tional detailsof construction of the protective guard apparatus and illustrating inphantom the various positions of the protective guard apparatus inrelation to corresponding positions of the tiltable lifting mastassembly; and

Figure 4 is a fragmentary front elevational view of the structure shownin Figure 3 and showing additional details of construction of theprotective guard apparatus provided in accordance with the principles ofthe present invention.

As shown on the drawings:

A lift truck is indicated generally by the reference numeral 10 and isprovided with a truck body or frame 11 mounted on longitudinally spacedwheels 12 and-13, respectively.

The lift truck 10 is provided with an enclosed power unit 14 located onone end of the truck body 11. in the preferred embodiment hereinillustrated, the power unit 14 comprises a battery energized prime moverand the enclosure takes the form of a battery box 16 closed by a cover17 which can be raised by grasping the handles 18 and pivotallydisplacing the cover 17 about the axis of a hinge 19 By opening thecover 17, convenient access is afforded to the battery box 16 so that aservicing operation may be effected. For example, it may be desirable inthe case of a battery energized prime mover to replace the batterieseach day of operation.

At the other end of the truck body 11 is provided a lifting mastassembly indicated generally at 24), the lifting mast assembly 20 beingpivotally connected to the truck body 11 by suitable pivot bracket means21. The lifting mast assembly 20 includes, by way of illustrativeexample, a fork lift 22 which can be effectively utilized in thehandling of industrial materials. The lifting mast assembly 20 istiltable, that is, it can be moved forwardly and backwardly in a mannerwell known in the art by a hydraulic actuating means including acylinder 23 housing a piston on the end of a piston rod 24 pivotallyconnected to a bracket 26 forming a part of the lifting mastassemblylil.

The lift truck 10 is fully dirigible and a steering control device 27together with other control apparatus is carried on a portion of thetruck body 11 forwardly of the power unit 14 so that an operator (notshown) standing in the space 28 may conveniently manipulate the variouscontrols of the truck 10 in order to elfect the regulation thereof. Anupright support member 29 forming a front portion of the truck body orframe 11 is provided to sup port the control apparatus and to rigidifyand strengthen the frame structure of the truck 10.

According to the principles of the present invention, a protective guardcanopy indicated generally by the reference numeral 30 is provided toextend horizontally superjacent the truck and particularly over the areanormally occupied by the operator so as to insure an adequate measure ofsafety for the operator.

More particularly, the protective guard canopy 30 comprises a pair ofgenerally parallel rail members 31 and 32 which are bent to assume anL-shaped configuration, thereby providing each rail member 31 and 32with a long leg 31a or 32a, respectively, and a short leg 31b or 32b,respectviely.

The L-shaped rail members are inverted so that the long legs 31a and 32aare positioned generally horizontally and extend rearwardly from aposition generally superjacent the lifting mast assembly 20, the ends ofthe rail members 31 terminating short of the end of the truck body orframe 11 on which the power unit 14 is mounted.

A plurality of cross bars 33 are extended between the long legs 32a and31a of the rail members 31 and 32 and are placed in firm assemblytherewith to provide a rigid frame structure. A foramionus screen 34 isfirmly assembled to the frame structure thus provided and forms aprotective covering over the head of the operator.

The rail members 31 and 32 being in parallel spaced alignment, the shortlegs 31b and 3212 form a yoke receiving an upper portion of the liftingmast assembly 20. The lifting mast assembly includes vertical sideframes 36 which are provided with a bracket 37 each carrying a pivot rod39 and receiving in pivotal support assembly the short legs 31b and 32bof the rail members 31 and 32. The protective guard canopy 30 is thuspivotally connected to the lifting mast assembly 20.

Along a medial portion of each of the long legs 31a and 32a of the railmembers 31 and 32, a link arm 40 is pivotally connected by means of apivot pin connection indicated generally at 41. The opposite end of eachof the link arms 40 is pivotally connected to the truck body or frame11. In order to effect such connection, a bracket 42 is connected oneach side of the upright support member 29 and is provided with a yoke43 holding a pivot pin 44. The link arm 40 is pivotally connected to thepin 44.

The spacing relationship between the pivot points established by thepivot pins 39, 41 and 44 insures that the protective guard canopyremains in substantial horizontal alignment even though the lifting mastassembly 20 is moved forwardly and backwardly by virtue of the tiltingaction thereof. This is illustrated graphically by the dotted linepositioning of the various related components as shown in Figure 3. Inthe dotted line showing on the right hand side of Figure 3, the verticalframe members 36 are moved rearwardly so that the short legs 31b and 32bof the rail members 31 and 32 pivotally move with respect thereto. Atthe same time, the lever arm 40 forms a radius arm about the pivot axis44 which is relatively stationary because it is on the truck body orframe 11. As a result, the protective guard canopy remains substantiallyhorizontal.

The dotted line showing on the left hand side of Figure 3 depicts thelifting mast assembly 20 with its vertical frame members 36 positionedforwardly. In this position, too, the protective guard canopy 30 issubstantially horizontal.

It will be noted that a particularly advantageous feature of the presentinvention resides in the fact that the protective guard assembly doesnot in any Way interfere with the convenient servicing access afiordedto the power unit 14 but at the same time a completely adequate measureof protection is provided for the operator of the truck.

Although various minor structural modifications might be suggested bythose versed in the art, it should be understood that I wish to embodywithin the scope of the patent warranted hereon all such modificationsas reasonably and properly come within the scope of my contribution tothe art.

I claim as my invention:

1. In combination, a lift truck having a body mounted on dirigiblewheels, a battery powered motor unit on one end of said body includingbattery storage means, a tiltable lifting mast pivotally connected tothe other end of said body, means forming an operator station betweensaid motor unit and said lifting mast, a stationary upright supportmember on said body between said operator station and said lifting mast,manually operable control means adjacent said upright support memberadapted to be manipulated by an operator carried on the truck at saidoperator station, an L shaped guard means having a horizontallyextending protective covering for the operator superjacent the body anda vertically extending connecting portion, connecting means pivotallyconnecting said vertically extending portion of said L shaped guardmeans to said lifting mast, and link means between said guard means andsaid upright support member, whereby said guard means remainsubstantially hori zontal upon tilting of said mast, said guard meansterminating short of a vertical plane erected at the said one end ofsaidbody to facilitate removal of batteries from said battery storage means.

2. A lift truck comprising a frame, a power unit at one end of saidframe, a cover on said power unit, hinge means for said cover to permitoverhead service of said power unit when said cover is open, a tiltablelifting mast on the other end of said frame, a guard canopy pivotallyconnected at one end to said lifting mast, and link arm means pivotallyconnecting said guard canopy to a portion of said frame intermediate thelifting mast and the power unit, said guard canopy comprising agenerally L-shaped screen member inverted to align the long leggenerally horizontally, the short leg of said screen member beingaligned generally vertically and being pivotally connected adjacent theend thereof to said lifting mast, and said link means being pivotallyconnected by means of said pivot connections at one of said oppositeends to said long leg at a medial portion thereof, said guard canopyterminating short of a vertical plane intersecting said one end of saidframe so as to permit overhead service of said power unit withoutinterference.

References Cited in the file of this patent UNITED STATES PATENTS2,143,983 Howell Ian. 17, 1939 2,263,978 Branovic et al Nov. 25, 19412,263,981 Dalecke et al. Nov. 25, 1941 2,479,623 Johnson Aug. 23, 19492,494,651 Flynn Jan. 17, 1950 2,621,821 Melin Dec. 16, 1952

